Comrade of Two Countries : A Soviet talk-show host who grew up in America says his dual identity cost himcredibility in both countries.

Out on Boylston Street, in front of a snow-covered Boston Common, a film student from Emerson College eagerly approached a familiar-looking figure.

“Excuse me,” Lauren Renihan, 21, said to the silver-haired man in the trench coat. “Aren’t you Mr. Vladimir?”

That is how identifiable Vladimir Posner has become to American followers of events in the Soviet Union. A frequent guest on shows like “Nightline” and “Donahue,” the 56-year-old Soviet journalist is said to be known to more Americans than any Russian other than Soviet leader Mikhail Gorbachev or his wife, Raisa.

But unlike the Gorbachevs, Posner speaks such perfectly unaccented American English that he might have been raised in Sacramento, or maybe St. Paul.

It turns out that this host of Soviet television’s two most widely viewed talk shows actually grew up in New York.

Living in Manhattan from age 6 to 15, “I never thought of myself as Russian,” said Posner, munching on Famous Amos cookies and sipping cranberry juice in the warmth of his hotel room. “I didn’t even speak Russian.”

In those years before McCarthyism took hold, Posner was the kind of normal, one might say All-American, kid who delivered newspapers, sparred in street fights and idolized Joe DiMaggio.

“The kids in school called me Vlady,” Posner remembered. It was a peculiarly American diminutive that never would have existed in Russia, the land of his father, where Posner and his parents settled when young Vladimir was 19.

The family had left the United States when Vladimir was 15 and his father had lost a high-paying job in the film industry. Their first stop was Germany, a country Posner abhorred. Finally, Posner, his parents and younger brother Paul established residence in his father’s home country.

“I didn’t return to Russia. I went,” said Posner, who was born in his mother’s homeland, France. “I had a strong dual identity. For a great many years, the Soviets would not really accept me as a legitimate Soviet. And I thought, ‘Who am I?’ ”

Eventually, Posner said, “I decided it didn’t matter. I know that I am the product of several different cultures and countries, and I relish that.”

Just as it has helped vault him to the status of perestroika superstar, Posner’s dual identity has both earned and cost him credibility on both sides of what was known before glasnost as the Iron Curtain. Critics in America and the Soviet Union alike have said he must be a KGB plant; how else could he be so incisive--and often so provocative--about these two radically different societies?

In the Soviet Union, he said, “there is still some suspicion that I am too Western.” Much the same doubts apparently exist in the United States, where a Harvard University professor whom Posner debated insisted that Posner have a Soviet flag in front of him so the audience would know which one was the Russian.

Along with his sharp opinions about both countries, Posner’s divided childhood is a major theme of his new book, “Parting With Illusions” (Atlantic Monthly Press, $19.95).

Though the book addresses the values, ethics and highly divergent national philosophies of both countries, it was in conjunction with that singularly capitalistic form of ritual torture--the book tour--that Posner and his wife, Katherin, were in Boston recently.

Posner said he has been amazed by what has taken place in his country since he began writing his book. In his wildest imagination, he said, he could not have constructed a Soviet Union where hundreds of thousands of people would march through the streets of Moscow to demand change; where the country’s leader would be discussing the possibility of multiparty elections; where a phrase like capitalistic socialism might entrench itself in the national vocabulary.

“I thought these changes might happen,” Posner said, spreading his arms in an expressive gesture. “But not in my lifetime.”

So much has happened in the Soviet Union, and in such a short time, that “nobody would have believed it,” he said. “Nobody.”

As Posner points out, “I am not the first one” to declare that the Cold War is over. Even Dan Quayle, the fervently anti-Communist vice president of the United States, was caught recently saying the Russians might not be so bad after all, Posner observed.

The changes in U.S.-Soviet relations and the tumultuous events in the Eastern Bloc have come so rapidly, Posner said, that many people on both sides of the globe have been left with their stereotypes showing.

If, in America, it is no longer fashionable to think of Russians as an entire nation of bad guys, Soviets are now reevaluating the old view of people in the United States as mindless and materialistic pawns of capitalism.

“Some of us are going to die with these stereotypes,” Posner said. On the other hand, many people are finding it “a tremendous relief” to let go of these unsavory images.

“At least the initial reaction is that if we can get together, then everything will be hunky-dory,” Posner said.

“One of the reasons Americans have been enthralled with Gorbachev is that for 45 years Americans have lived under the shadow of nuclear annihilation,” he went on. “When all of a sudden, it seemed that the big, bad Commies were not that bad, there was this huge sigh of relief.”

Just exhaling all those ugly old images “brought Americans halfway out of their chairs,” Posner said.

But, he cautioned, “halfway out is a very uncomfortable position. If something goes wrong, they will go right back” to their old preconceptions.

In his book, as on television, Posner often weighs in with opinions about America that many people do not like to hear.

“I have been accused by some Americans of what they call bashing America,” he said. “I laugh. I say, ‘You guys have been bashing the Soviet Union for years, and when somebody says something you don’t like, you get up on your high horse.’

“If you like America--and I do--there is a lot to criticize,” Posner said. “Poverty would be the first thing, and hunger, and then that America consistently preaches on the issue of human rights around the world and is not always where it ought to be on that issue in its own country.”

Criticism of pre- perestroika Russia was a lot easier, Posner said, because officially, anyway, there was no criticism. “You didn’t have to think.” Now, he said, “if people in the Soviet Union are critical of Gorbachev, one reason is that he has made it more complicated than it used to be, by presenting more choices.

“Some would like the authoritarian father-figure leader to come back and say, ‘Children, this is what we are going to do,’ ” Posner said.

But he rebuts those who think such a figure might be V. I. Lenin, the father of socialism, or those who say that the events in the Soviet Union today have Lenin turning in his tomb in Red Square.

“Maybe for the first time in nearly 70 years, Lenin has stopped turning in his grave,” Posner said. “What we have had has been anything but the socialism envisaged by Lenin.

“What I think we may be seeing now is an attempt to go back to the original ideas of the revolution,” he said. “That is what Gorbachev has been talking about.”

But philosophical change is not the only thing his compatriots are after, Posner said.

“More than anything else, they want more in the stores,” he said. “They want more meat, more vegetables, more fruit. Most of all, they’re sick and tired of standing in line.”

Five years ago, Posner said, Soviet consumers would have said, “Yes, it’s tough, but you have to do it for the greater good of the state.” Today, “that is what is changing, the idea that you have to sacrifice for the greater goal of the future. That is finished.”

Over the years, Posner’s own sense of disillusionment with the Soviet Union has been so high that he came close to emigrating. During a world youth festival in Moscow in 1957, he recalled spending two weeks living in a Moscow University dormitory with some students from the United States.

“I suddenly realized I was homesick--for New York City,” he said. “I wanted to go back.”

Twenty years later, when Posner was a successful magazine journalist, his request to travel abroad was denied by Soviet authorities.

“It was like being told I was a second-class citizen, not worthy of trust,” he said. “It hurt so damned much” to feel rejected by his own government that Posner said he began “drinking too much” and talking about emigrating.

“I felt betrayed, frustrated beyond anything I could explain,” he said.

But Posner persevered, adhering to his belief that “if you could just not betray yourself, then you will win.

“Let me tell you,” he said, “if there is one quality that I may have, it is the ability to hang tough.” Still, he said, reverting to a decidedly un-Soviet idiom, “a couple of times I nearly copped out.”

Posner maintained his sense of connection to the United States through movies, through reading novels he obtained from the Book-of-the-Month Club and through meeting with Americans who traveled to the Soviet Union. It was as if, he said, he had “this subconscious desire” not to lose his ties to the United States.

“I really wanted to be this link,” he said. “What I have tried to do in my limited way is to help Soviets understand Americans in a more, how shall I put this, in a more human way.”

The thawing of Cold War barriers has left Posner with a sense of new hope for the two countries he has lived in and loved, and for the planet as a whole.

“I think people can really look forward to the 21st Century,” he said. “It may finally be the flowering of the human race.”

But before that can happen, Posner has an agenda of his own, and that is to finish rewriting his book in Russian. Translation would not work, the one-time translator said, because even with glasnost, the cultural differences remain too vast. “For instance, if I write that Joe DiMaggio was my hero, I would have to explain it to a Soviet reader.”

Posner smiled, and the blue eyes that have helped make him the leading television personality in the Soviet Union twinkled. It’s cumbersome to have to rewrite the whole book, he said. But alas, “I haven’t yet mastered the art of writing in two languages at once.”